Embodiments of the invention relate to an image sensor and a method of manufacturing the image sensor.
An image sensor is a semiconductor device converting an optical image into electrical signals. Image sensors may be classified into a charge coupled device (CCD) image sensor and a complementary metal oxide silicon (CMOS) image sensor (CIS).
A unit pixel of a CMOS image sensor includes a photodiode and one or more metal oxide silicon (MOS) transistors. Therefore, the CMOS image sensor sequentially detects an electrical signal of the unit pixel in a switching manner to generate an image. The CIS includes a photodiode region converting a light signal into an electrical signal and a transistor processing the electric signal, and the photodiode region and the transistor are horizontally arranged.
The photodiode of the horizontal type CIS is horizontally adjacent to the transistor on the substrate. Therefore, an additional region is required for forming the photodiode region, thereby reducing a fill factor and limiting resolution.